The present invention relates to a metal laminate gasket with different coating layers.
A metal laminate gasket formed of a plurality of metal plates has been known and used in an internal combustion engine, as a cylinder head gasket and a manifold gasket.
In case a cylinder head and a cylinder block are formed, surfaces of the cylinder head and the cylinder block with which the gasket contacts may be ground to form finishing surfaces. As a result, small scratches, such as cutter tracing, are formed.
It is preferable to have a smooth contact with the cylinder head and the cylinder block to securely seal between the cylinder head and the cylinder block. Therefore, a cylinder head gasket may have coating layers on one or both surfaces thereof to fill out the small scratches by the coating layers. Plating may be formed on the gasket instead of the coating.
Also, in the metal laminate gasket, fluid may enter into a space between the plates. In order to prevent fluid from entering into the space between the plates or to prevent fluid when it is entered into the space from freely flowing in the space, a coating layer may be formed in one of two plates contacting with each other.
The coating layers formed on or situated between the metal plates have been known already in the art, but the coating layers have specific characteristics, such as weakness in heat and pressure, depending on materials contained therein. For example, if high pressure and heat are applied to such a material, the coating may flow to cause reduction of a surface pressure. In this case, the sealing may not be properly made.
In view of the foregoing, the present invention has been made, and an object of the invention is to provide a metal laminate gasket with coating layers, which can properly seal between the plates as well as relative to the cylinder head and cylinder block.
Another object of the invention is to provide a metal laminate gasket as stated above, which can securely seal around a fluid hole.
Further objects and advantages of the invention will be apparent from the following description of the invention.